S355J2 Carbon Steel Round Bar — Factory Direct Supplier | Huaxia-Steel

S355J2 round bar is the high-availability structural bar grade European fabricators reach for when a part must carry real load and survive sub-zero conditions. Supplied to EN 10025-2 with a guaranteed 355 MPa minimum yield strength and full Charpy impact testing at −40°C (the J2 designation), it bridges the gap between plain construction grades like S235JR and the higher-cost alloy steels. We supply S355J2 round bar direct from the factory in diameters from 20 mm to 300 mm, in random lengths or cut-to-length with machining-ready tolerances.

Every bar ships with an EN 10204 3.1 mill test certificate showing the actual heat chemistry and mechanical results, including the −40°C impact values. For export projects we handle bundling, rust protection, ISPM 15 compliant dunnage and container or break-bulk loading, and third-party inspection (SGS, BV, TÜV) can be arranged before shipment on request.

Product Overview

S355J2 round bar is produced as hot rolled bar from continuously cast blooms, with optional bright drawn or peeled finish for machining stock. The J2 subgrade guarantees Charpy V-notch energy of 27 J minimum at −40°C in the longitudinal direction, which is what makes the grade suitable for offshore adjacent structures, crane components, cold-storage frames and outdoor equipment in northern climates.

Compared with S355JR (tested at room temperature only), the J2 variant costs modestly more but removes the temperature qualification risk on any project with a cold-climate specification. Compared with C45, the S355J2 bar offers far better weldability and impact toughness, at the cost of lower surface hardness — it is a structural grade, not a wear grade, and specifying it as such avoids both over-buying and under-specifying.

Dimensions and Tolerances

Parameter	Range	Tolerance / Note
Diameter (hot rolled)	20–300 mm	EN 10060 class 1/2, ±0.4–1.5%
Diameter (bright drawn)	16–100 mm	h9–h11 per EN 10278
Length (random)	3–6 m	±50 mm standard
Length (cut to length)	up to 12 m	±2 mm on request
Straightness	≤3 mm/m	≤1 mm/m on request
Bundle weight	≤5 t	strapped, oiled, tagged per heat

Cut-to-length service includes saw cutting with square or bevelled ends, chamfering, and optional pre-machining to blank dimensions so your shop receives bars ready for the lathe. Marking is by low-stress die stamping or paint stencil showing grade, heat number and size, so traceability survives unpacking on your shop floor.

Chemical Composition (EN 10025-2, heat analysis)

Element	C	Si	Mn	P	S	Cu (max)
Range	≤0.20%	≤0.55%	≤1.60%	≤0.035%	≤0.035%	0.55%

The carbon equivalent (CEV) is controlled to ≤0.45% typical, keeping the grade readily weldable with standard consumables and minimal preheat for section sizes used in bar work. Where your welding procedure requires tighter limits, we can supply heats selected to a restricted analysis — confirm at enquiry stage so the mill allocates the right melt.

Mechanical Properties

Property	Requirement (longitudinal)	Typical delivered
Yield strength (≤16 mm)	≥355 MPa	380–450 MPa
Tensile strength	470–630 MPa	500–580 MPa
Elongation A5	≥20%	22–26%
Charpy V-notch	≥27 J at −40°C	60–120 J
Hardness	—	146–170 HB

Impact testing is performed per heat and thickness class with EN 10045/ISO 148 Charpy specimens. Bars above the standard test class thickness, or destined for particularly severe service, can be supplied with through-thickness (Z-grade) testing on request.

Manufacturing Standards and Supply Conditions

• EN 10025-2 — hot rolled structural steel, non-alloy, J2 subgrade (impact at −40°C).
• EN 10060 — dimensional and mass tolerances for hot rolled round bars.
• EN 10278 — bright steel products, dimensional tolerances for drawn/peeled bar.
• EN 10204 3.1 — specific inspection certificate standard for every delivery.
• Nearest equivalents: Q355D (GB/T 1591), ASTM A572 Gr50 (no J2 equivalent — review toughness), SM490C (JIS) — supplied only with engineering sign-off.

Supply conditions available: as-rolled (+AR), normalized (+N), normalized rolled (+NR), and stress-relieved for precision bar. Most stock ships as-rolled; normalized condition is quoted when forming or impact requirements justify it.

Applications

• Shafts, axles and pins for construction and mining equipment operating in cold regions.
• Structural pins, bolts and connectors for cranes, offshore-adjacent platforms and bridges.
• Cold-storage building frames and refrigerated warehouse structures.
• Machined components — gear blanks, flanges, couplings — where weldability matters.
• Renewable energy structures: tower internals, foundation bolts, yaw system parts.

Because the grade combines 355 MPa yield with −40°C toughness and clean weldability, it is often the single bar grade that lets a fabricator unify structural and machined parts on one material certificate — simplifying both procurement and workshop quality control.

Quality Assurance

• EN 10204 3.1 MTC with heat chemistry, tensile and Charpy results for every delivery.
• Impact testing at −40°C witnessed and reported per heat/thickness class.
• Dimensional inspection to EN 10060/EN 10278 with reported diameter, ovality and straightness.
• Surface inspection: no laps, seams or heavy scale; bright bar surface to EN 10278.
• Ultrasonic testing (SEP 1927 / EN 10308) available on request for critical bar.
• Third-party inspection (SGS, BV, TÜV) arranged before shipment on request.

Packaging and Export Shipping

Bars are bundled at 1–5 t with steel strapping, end-protected, lightly oiled against transit rust, and tagged with grade, heat number and bundle weight. Export packing includes ISPM 15 compliant timber dunnage, seaworthy crating for bright bar, and container loading with dunnage bags to prevent transit movement. Standard container lengths up to 5.8 m; longer bars ship break-bulk or in 40 ft open-top units.

We ship FOB, CFR and DAP to major ports worldwide from Chinese and Korean loading points, with typical stock delivery in 5–10 days and mill-rolled special sizes in 3–5 weeks. Tell us the grade, diameter, length and destination port and we will return a firm quote with lead time within 24 hours.

How S355J2 Compares With Neighbouring Grades

Grade	Yield (min)	Impact test temp	Choose when
S235JR	235 MPa	+20°C	Non-critical parts, lowest cost
S355JR	355 MPa	+20°C	Load-bearing parts, mild climate
S355J2	355 MPa	−40°C	Cold service, code-toughness specs
Q355D	355 MPa	−40°C	Chinese standard equivalent
C45	—	—	Wear parts needing hardness, not toughness

The table shows the two decisions buyers actually face. First, JR versus J2: identical strength, different temperature qualification, so the project’s lowest design temperature decides. Second, structural versus machining grade: S355J2 wins on welded structural parts, while C45 wins on wear parts that will be heat treated — forcing one grade to do the other’s job always costs more somewhere else.

Machining and Welding S355J2 Bar

S355J2 machines competently at medium speeds with coated carbides — roughly comparable to 1020, below dedicated free-machining grades. For shaft work it is common to rough machine, stress relieve at 550–600°C if the part is slender, then finish machine. Surface hardness is modest (around 150–170 HB), so wear surfaces are usually induction hardened or replaced with a sleeve after machining — a standard shaft-building pattern rather than a limitation.

Welding is straightforward: standard ER70S-6 or matching S355 consumables, no preheat for bar sections under about 25 mm in ambient conditions, and a modest 100°C preheat for heavier assemblies in cold shops. Because the grade’s carbon equivalent is controlled, welding procedure qualification is routine, and fabricated shaft assemblies of S355J2 bar with plate attachments weld without special measures.

Storage and Transit Rust Protection

S355J2 bar is not a weathering grade and will surface-rust in humid storage. We protect shipments with a light oil film, VCI paper interleaving on bright bar, and sealed bundles; on arrival, stock should be stored off the ground with airflow between bundles. Surface rust on hot rolled bar is cosmetic and cleans off in machining, but bright bar customers who need as-drawn finish should specify oiled and VCI packing explicitly — it is standard on our export orders.

Ordering Workflow and Lead Times

Stock diameters in the common 20–150 mm range ship within 5–10 days of order confirmation; mill-rolled special diameters above 150 mm and normalized-condition bar run 3–5 weeks. To quote accurately we need grade (with subgrade — J2), diameter and tolerance class, length (random or cut), quantity in tonnes or pieces, and destination port. Testing extras — impact witness, UT, third-party inspection — should be named at enquiry because they schedule mill resources.

Repeat buyers usually set up a stocking program: we hold agreed diameters and release against call-offs, which smooths your shop’s supply and captures the mill’s rolling cycle. Ask for the stocking program terms with your first order if the same S355J2 sizes recur across projects.

All S355J2 round bar from Huaxia-Steel ships with EN 10204 3.1 certification as standard, export packing engineered for sea transit, and a sales engineer who answers grade and machining questions before you commit. Send your enquiry with grade, sizes, quantity and destination — we will confirm stock, lead time and a firm price the same working day.

Typical S355J2 bar orders we ship weekly include: 40–120 mm diameters for machined shafts and pins in construction equipment, 20–60 mm bar for cold-storage structural connectors, and 150–300 mm heavy sections for forged and machined components. If your sizes sit between stock points, ask about peeled or drawn-to-size supply before accepting an oversize machining allowance — buying closer to net shape often costs less than machining the difference.